Transformer terminal compartment cover means

ABSTRACT

Terminal compartment cover means for pad mounted transformers of the type having a tank integral with high and low voltage terminating compartments. The cover means comprises first and second covers enclosing the high voltage and low voltage segments of the compartment in a manner which permits isolation of the high voltage segment when the low voltage segment is opened. Each cover is of inverted L-shaped cross section when closed, hinged along its upper edge to the tank and padlocked at its lower edge. The high voltage segment cover has a barrier facing the low voltage side which prevents access to the high voltage terminals. Interfitting water drainage channel means are provided on the two covers.

United States, Patent [191 Broverman TRANSFORMER TERMINAL COMPARTMENT COVER MEANS Inventor: Alvin Y. Broverman, Versailles, Ky.

Assignee: Kuhlman Corporation, Troy, Mich.

Filed: Oct. 15, 1973 Appl. No.: 406,186

US. Cl. 3l7/l57.6, 317/15 Int. Cl. HOlf 27/00 Field of Search 317/15, 157.6, 157.61, 317/120; 174/15 R, 16 R, 52 R; 312/100; 220/32, 33; 16/169 References Cited UNITED STATES PATENTS Mar. 11, 1975 Primary Examiner-J. D. Miller Assistant ExaminerHarry E. Moose. Jr. Attorney, Agent. or FirmHarness, Dickey & Pierce [57 ABSTRACT Terminal compartment cover means for pad mounted transformers of the type having a tank integral with high and low voltage terminating compartments. The cover means comprises first and second covers enclosing the high voltage and low voltage segments of the compartment in a manner which permits isolation of the high voltage segment when the low voltage segment is opened. Each cover is of inverted L-shaped cross section when closed, hinged along its upper edge to the tank and padlocked at its lower edge. The high voltage segment cover has a barrier facing the low voltage side which prevents access to the high voltage terminals. lnterfitting water drainage channel means are provided on the two covers.

6 Claims, 6 Drawing Figures TRANSFORMER TERMINAL COMPARTMENT COVER MEANS BACKGROUND OF THE INVENTION 1. Field of'the Invention The invention relates to pad mounted transformers having a transformer tank assembled integral with a high and low voltage terminal compartment. This compartment must be both tamper and weather resistant with no exposed, externally defeatable fastening devices. There should be no openings through which objects such as wires may be inserted and only limited entry of water is permissible. Since utility companies normally have separate high and low voltage ratings for operating personnel, these two segments of the compartment must be independently lockable and separated by a suitable barrier. While unlocking of the low voltage compartment segment will permit access only to this portion of the equipment, the high voltage segment should not be accessible until additional specific action is taken.

2. Description of the Prior Art Types of existing compartment cover constructions include: (a) Two horizontally movable hinged front opening doors; (b) A single flip-top lid comprising front, top and sides which pivots vertically back onto the tank to permit access to the entire compartment; and (c) A "clam shell construction permitting access to the compartment by two doors each comprised of a front, top and side, said doors swinging open horizontally in opposing directions.

With the horizontally swinging front opening doors, the stationary compartment sides and top create dangerously close ground surfaces for the primary loadbreak terminators and/or pull-out bayonet fuses. This construction is relatively complicated and renders cramped working quarters for connecting cables or servicing equipment. It requires a complex and remote latching arrangement and has an excessive number of openings which must be made tamper resistant.

The clam shell construction overcomes most objections to the two horizontally swinging frontopening door compartments but is structurally unstable and unsuitable for wide units due to excessive cantilever forces on the hinges.

The single flip-top compartment permits adequate working space and electric clearances, direct latching and simplified construction, and a reduced number of openings requiring tamper provisions. However, on wide or tall units the door has excessive weight and furthermore has no inherent means for isolating the high voltage segment when only low voltage segment entry is required.

BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide novel and improved transformer terminal compartment cover means which overcomes the disadvantages of previous constructions, requires minimum lift weight and automatically provides for isolation of the high voltage compartment segment when the low voltage segment is opened.

Briefly. the illustrated embodiment of the invention comprises a high voltage and a low voltage cover alongside each other, each cover having atop, a front and an outside wall, the high voltage cover additionally having a barrier integral therewith between the high voltage '2 and low voltage segments, the top of each cover bring independently hinged to the tank top, each cover having means for independently locking the cover when in a closed position, whereby swinging open of the low voltage cover will permit access to the low voltage terminals from the front and one side of the transformer but will not permit access to the high voltage terminals.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pad mounted transformer utilizing the principle of this invention, the covers being in their closed positions;

FIG. 2 is a fragmentary perspective view with the low voltage cover open;

FIG. 3 is a fragmentary front elevational view of the transformer with both covers in their open position;

FIG. 4 is a fragmentary top plan view with the covers closed;

FIG. 5 is a fragmentary side cross-sectional view along the line of 5-5 of FIG. 4; and

FIG. 6 is a fragmentary front cross-sectional view in elevation showing the interfitting water drainage means, along line 6-6 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The transformer is generally indicated at I! installed on a concrete pad or base 12 and comprises a tank 13 of rectangular shape. Wall 14 of tank 13 has a plurality of high voltage terminals and insulated separable connector park stands 15 and low voltage terminals 16 extending therefrom above base 12. As seen in FIG. 3, the high voltage terminals usually occupy a major portion of wall 14 starting at the left-hand side whereas terminals 16 are on the right-hand side. A vertical flange 17 extends along the wall separating the two sets of terminals.

A U-shaped sill 18 is secured at its ends to the lower portion of side walls 19 of tank 13 and extends outwardly therefrom. The front wall of this sill has a pair of locking recesses 20 and 21 for the covers of this invention. Each recess has a staple 22 through which a padlock may be passed.

The cover means of this invention is generally indicated at 23 and comprises a high voltage cover generally indicated at 24 and a low voltage cover generally indicated at 25. Cover 24 comprises a top 26, a front wall 27, an outside wall 28 and a barrier wall 29 parallel to wall 28. Top 26 is hinged along one edge to top 13 of tank 19 by a pair of hinges 31 and 32. These hinges permit cover 24 to be swung between a closed position shown in FIG. I and an open position in FIG. 3. In its closed position, cover 24 encloses high voltage terminals 15. The lower edge of front wall 27 interfits with a recessed lip 33 along the top edge of sill l8. Barrier 29 is adjacent and overlaps the high voltage side of flange 17, its lower edge being at the top level of sill 18. Side wall 28 also tits in recess 33 of sill 18, top 24 and side wall 28 being substantially flush with the adjacent top and side walls of tank 13 when cover 24 is closed. A hasp 34 is secured to the lower edge of front wall 27 and has a slot receiving staple 22 so that a padlock may be used to lock the high voltage cover.

Low voltage cover 25 is shaped similarly to cover 24. It has a top 35, a front wall 36 and outside wall 37; however, it does not have an inside wall equivalent to barrier 29, as is evident from FIG. 2. This cover is hinged to the top of tank 13 by hinges 38 and 39.

A hinge stop in the form of a curved member 41 'is bolted to wall 14 and extends through the gap between rear edge 42 of cover 25 and a hinge supporting member 43 which is part of tank 13. This stop is aligned with hinge 39 to prevent hinge disengagement or accidental sideways movement when opening cover 24. Stop 41 may be unbolted from the inside when removal is desired (FIG. A similar hinge stop 41 is provided for high voltage cover 24. Like cover 24, cover 25 interfits with lip 33 of sill l8, and has a hasp 44 for its staple 22. The two covers may thus be independently locked.

Means are provided for minimizing water leakage into the terminal compartment. The rear edges 42 of the covers (FIG. 5) are recessed and overlap hinge by supporting members 43 which is part of tank 13. The outside walls 28 and 37 of the covers have recessed lips 45 interfitting with side flanges 46 on tank 13 (FIGS. 2 & 3). Cover 24 has a channel 47 along its top and front adjacent barrier 29 (FIGS. 2 and 6) which receives a lip 48 along the top and front of cover 25. This interfitting water drainage means will insure minimum entry of water into the terminal compartment segments, and also provides resistance to tampering.

In use, both covers 24 and 25 will normally be closed and locked, the closed positions being shown in FIG. 1.

In its closed position the cover means has a minimum of openings through which insertion of wires or other objects may be attempted. Ifa person wishes to gain access to low voltage terminals 16, he must unlock and swing back cover 25 toits FIG. 2 position, top 35 resting on tank 13. This provides easy access to these terminals, but at the same time allows no direct access to high voltage terminals because of barrier 29. Since cover 25 does not extend the full width of the transformer, its lifting weight will not be excessive.

When it is desired to gain access to high voltage terminals 15, both covers will be unlocked and swung back to their FIG. 3 positions. The covers will rest on tank 13 and ready access may be had to both sets of terminals.

What is claimed is:

I. In combination with a transformer tank having high voltage and'low voltage terminals extending from separate portions of a side wall, cover means comprising a high voltage. and a low voltage cover alongside each other, each cover having a top, a front and an outside wall, the high voltage cover additionally having a barrier integral therewith between the high voltage and low voltage segments, said low voltage cover additionally having a portion overlapping said high voltage cover when said covers are in a closed position, the top of each cover being independently hinged to the tank top, each cover having means for independently locking the cover when in a closed position, whereby swinging open of the low voltage cover will permit access to the low voltage terminals from the front and one side of the transformer but will not permit access to the high voltage terminals.

2. The combination according to claim I, further provided with a sill below said covers and interfitting with the lower edges thereof when the covers are closed, said locking means being partially carried by said sill and partially by said covers.

3. ,In combination with a transformer tank having high voltage and low voltage terminals extending from separate portions of a side wall, cover means comprising a high voltage and a low voltage cover alongside each other, each coverhaving a top, a front and an outside wall, the high voltage cover additionally having a barrier integral therewith between the high voltage and low voltage segments and a water drainage and tamperresisting channel along its top and front adjacent said barrier, said low voltage cover additionally having'a lip interfitting with said channel, the top of each cover being independently hinged to the tank top, each cover having means for independently locking the cover when in a closed position, whereby swinging open of the low voltage cover will permit access to the low voltage terminals from the front and one side of the transformer but will not permit access to the high voltage terminals.

4. The combination according to claim 3, further provided with a hinge stop on each of said low voltage and high voltage covers interengageable with a hinge thereon to prevent removal ofthese covers, and means accessible only from the inside of the respective covers for removing said stop.

5. A transformer comprising a tank having a top and a wall of rectangular shape, a set of high voltage terminals on one portion of said wall extending from one side 7 thereof, a set of low voltage terminals on another portion of said wall extending from the other side, a vertical flange on said wall between said sets of terminals, a high voltage cover having a top, front and outside wall, the top being hinged to the top of said tank, a bar rier wall on said high voltage cover between said sets of terminals, a sill extending from the lower portion of said tank wall, the high voltage cover being swingable between a closed position interfitting with said sill and tank wall and an open position in which the top is swung back against the tank top, the barrier wall closelyoverlapping said flange when the high voltage cover is closed, a low voltage cover having a top, front and outside wall, said top being hinged to the top of said tank, the low voltage cover being swingable between a closed position enclosing said low voltage terminals and an open position resting against the top of said tank, and independent interfitting locking means on said sill and the front walls of said two covers, whereby they may be separately locked closed.

6. The combination according to claim 5, further provided with a water drainage and tamper-resisting channel along the top and front of said high voltage cover adjacent said barrier, and a lip along the top and front of said low voltage cover interfitting with said channel. 

1. In combination with a transformer tank having high voltage and low voltage terminals extending from separate portions of a side wall, cover means comprising a high voltage and a low voltage cover alongside each other, each cover having a top, a front and an outside wall, the high voltage cover additionally having a barrier integral therewith between the high voltage and low voltage segments, said low voltage cover additionally having a portion overlapping said high voltage cover when said covers are in a closed position, the top of each cover being independently hinged to the tank top, each cover having means for independently locking the cover when in a closed position, whereby swinging open of the low voltage cover will permit access to the low voltage terminals from the front and one side of the transformer but will not permit access to the high voltage terminals.
 1. In combination with a transformer tank having high voltage and low voltage terminals extending from separate portions of a side wall, cover means comprising a high voltage and a low voltage cover alongside each other, each cover having a top, a front and an outside wall, the high voltage cover additionally having a barrier integral therewith between the high voltage and low voltage segments, said low voltage cover additionally having a portion overlapping said high voltage cover when said covers are in a closed position, the top of each cover being independently hinged to the tank top, each cover having means for independently locking the cover when in a closed position, whereby swinging open of the low voltage cover will permit access to the low voltage terminals from the front and one side of the transformer but will not permit access to the high voltage terminals.
 2. The combination according to claim 1, further provided with a sill below said covers and interfitting with the lower edges thereof when the covers are closed, said locking means being partially carried by said sill and partially by said covers.
 3. In combination with a transformer tank having high voltage and low voltage terminals extending from separate portions of a side wall, cover means comprising a high voltage and a low voltage cover alongside each other, each cover having a top, a front and an outside wall, the high voltage cover additionally having a barrier integral therewith between the high voltage and low voltage segments and a water drainage and tamper-resisting channel along its top and front adjacent said barrier, said low voltage cover additionally having a lip interfitting with said channel, the top of each cover being independently hinged to the tank top, each cover having means for independently locking the cover when in a closed position, whereby swinging open of the low voltage cover will permit access to the low voltage terminals from the front and one side of the transformer but will not permit access to the high voltage terminals.
 4. The combination according to claim 3, further provided with a hinge stop On each of said low voltage and high voltage covers interengageable with a hinge thereon to prevent removal of these covers, and means accessible only from the inside of the respective covers for removing said stop.
 5. A transformer comprising a tank having a top and a wall of rectangular shape, a set of high voltage terminals on one portion of said wall extending from one side thereof, a set of low voltage terminals on another portion of said wall extending from the other side, a vertical flange on said wall between said sets of terminals, a high voltage cover having a top, front and outside wall, the top being hinged to the top of said tank, a barrier wall on said high voltage cover between said sets of terminals, a sill extending from the lower portion of said tank wall, the high voltage cover being swingable between a closed position interfitting with said sill and tank wall and an open position in which the top is swung back against the tank top, the barrier wall closely overlapping said flange when the high voltage cover is closed, a low voltage cover having a top, front and outside wall, said top being hinged to the top of said tank, the low voltage cover being swingable between a closed position enclosing said low voltage terminals and an open position resting against the top of said tank, and independent interfitting locking means on said sill and the front walls of said two covers, whereby they may be separately locked closed. 